# demo for nested loops

for x in range(4):
    for y in range(3):
        print(f"({x}, {y})")


numbers = [5, 2, 5, 2, 2]


# 打印出字母 "F"
def print_f(size):
    for i in range(size):
        for j in range(size):
            if i == 0 or i == size // 2:
                print("X", end=" ")
            elif j == 0:
                print("X", end=" ")
            else:
                print(" ", end=" ")
        print()


# 测试打印字母 "F"，size = 5
print_f(5)


numbers = [5, 2, 5, 2, 2]
for count in numbers:
    print("K" * count)
